1. Field of the Invention
The present invention relates to an oscillator device used in, for example, an endoscope, and a transmitter module using the oscillator device.
2. Description of the Related Art
There is a known inspection device for looking inside the patient's body. The inspection device includes a very small oscillator device, which is swallowed by the patient, and a receiving antenna, which is provided outside the patient's body and receives electric waves emitted from the oscillator device.
Such an oscillator device has generally a directional transmitting antenna since it is needed to have a very small size. The oscillator device, which travels in the patient's body, changes its position and direction over time. Accordingly, a receiving device has multiple receiving antennas to receive directional electric waves emitted from various positions and directions. Specifically, the receiving antennas are attached on the patient in different directions so as to receive electric waves emitted from all directions.
For example, Japanese Patent Application Laid-open No. H3-49303 discloses an oscillator circuit related to the above oscillator device.
As described above, the receiving device, if having a few receiving antennas, is difficult to receive electric waves with homogeneous strength from the directional transmitting antenna of the conventional oscillator device. To overcome this problem, an approach is that multiple receiving antennas 3 are arranged around the organs 2 of the patient 1, as shown in FIG. 10. However, this arrangement increases the burden on the patient.